EP1516470B1 - Procede d'egalisation et de demodulation d'un signal de donnees transmis par l'intermediaire d'un canal variable dans le temps - Google Patents

Procede d'egalisation et de demodulation d'un signal de donnees transmis par l'intermediaire d'un canal variable dans le temps Download PDF

Info

Publication number
EP1516470B1
EP1516470B1 EP03760586A EP03760586A EP1516470B1 EP 1516470 B1 EP1516470 B1 EP 1516470B1 EP 03760586 A EP03760586 A EP 03760586A EP 03760586 A EP03760586 A EP 03760586A EP 1516470 B1 EP1516470 B1 EP 1516470B1
Authority
EP
European Patent Office
Prior art keywords
data
scatterer
scatterer coefficients
measurement
coefficients
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP03760586A
Other languages
German (de)
English (en)
Other versions
EP1516470A1 (fr
Inventor
Rainer Bott
Ulrich Sorger
Snjezana Gligorevic
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rohde and Schwarz GmbH and Co KG
Original Assignee
Rohde and Schwarz GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rohde and Schwarz GmbH and Co KG filed Critical Rohde and Schwarz GmbH and Co KG
Publication of EP1516470A1 publication Critical patent/EP1516470A1/fr
Application granted granted Critical
Publication of EP1516470B1 publication Critical patent/EP1516470B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L25/03178—Arrangements involving sequence estimation techniques
    • H04L25/03248—Arrangements for operating in conjunction with other apparatus
    • H04L25/03292—Arrangements for operating in conjunction with other apparatus with channel estimation circuitry
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/01—Equalisers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/22—Demodulator circuits; Receiver circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
    • H04L2025/03375—Passband transmission
    • H04L2025/03414—Multicarrier
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/03433—Arrangements for removing intersymbol interference characterised by equaliser structure
    • H04L2025/03439—Fixed structures
    • H04L2025/03445—Time domain
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/03433—Arrangements for removing intersymbol interference characterised by equaliser structure
    • H04L2025/03439—Fixed structures
    • H04L2025/03522—Frequency domain
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/024—Channel estimation channel estimation algorithms
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L25/03178—Arrangements involving sequence estimation techniques
    • H04L25/03248—Arrangements for operating in conjunction with other apparatus
    • H04L25/03286—Arrangements for operating in conjunction with other apparatus with channel-decoding circuitry

Definitions

  • the invention relates to a method for equalization and for demodulating a via a time-varying channel transmitted to a receiver data signal.
  • ISI Intersymbol interference
  • ICI Interchannel Interference
  • a method for the equalization of DVB-T on the The basis of the assumption of constancy is, for example, in Burow-R; Fazel-K; Hoeher-P; Klank-O; Kussmann-H; Pogrzeba-P; Robertson-P; Ruf-M-J "On the performance of the DVB-T system in mobile environments "IEEE GLOBECOM 1998 described.
  • the method according to the invention is no longer the Channel impulse response used for the channel estimation, but rather the so-called scatterer coefficients, namely the complex valued attenuation, the delay and the Doppler shift in the port.
  • the so-called spreader (Scatterer) caused reflections between a transmitter and receiver radiated signal are the cause of the quality of the transmission channel, like this for example, is described in the book of Raymond Steele, "Mobile Radio Communications", Pentech Press, London, 1992, section 2.3.1.
  • Such scatterers as Buildings or vehicles distort that between transmitter and Receiver transmitted data signal.
  • On the distorted Data signal can in the receiver this on the scatterer ascertained Scatterer coefficients which then equalizes the distorted data signal and finally demodulated.
  • According to the Invention thus become the channel properties through this Scatterer coefficients defined in the sense of following description in a simple manner from the received distorted data signals are determined can.
  • Equation 1 shows, on the basis of a two-dimensional field, the discretization of the Doppler frequency f d and the delay ⁇ in the transmission channel for different scatterers.
  • This graph can be directly converted into a scatterer matrix S having the scattering coefficients S (m, k) as used in equations (1) to (4) below.
  • the coefficients of the matrix S represent the complex-valued attenuation values (amplitude and phase).
  • the quantization in the delay direction ⁇ and in the Doppler shift direction f d depends on the channel and data transmission method.
  • the maximum values K for the discrete normalized Doppler shift and M for the discrete normalized deceleration are given by the physical parameters of the channel.
  • Fig. 1 Five scatterers are shown, whose indices correspond to the position in the scatter matrix; the Numbering starts here with 1.
  • This physical model thus takes into account the geometry of the propagation model of the channel rather than the impulse responses.
  • This geometry and thus the delay ⁇ and Doppler shift f d associated with the respective scatterer, remains practically constant for sufficiently long times, since transmitters and / or receivers can not move as fast as desired or can perform arbitrarily fast changes in movement.
  • the impulse response of the channel can, in principle, vary arbitrarily within the permissible physical limits.
  • the discrete impulse response is calculated from the complex scatterer coefficients S (m, k)
  • K is the maximum occurring Doppler frequency
  • m is the running index for the delay
  • i is the discrete running variable for the time.
  • h (i) is the resulting discrete temporal impulse response of the channel. It is considered over the length N.
  • the maximum likelihood approach for the determination of the scatterer coefficients matrix S in the time domain yields by minimizing the subsequent expression after the scatterer coefficients.
  • the data symbols are either known directly as Training sequence provided or they will be out of the received signal through the following Method determined.
  • the estimation of the scatterer coefficients in the time domain is preferably used in data transmission methods used, which work in the time domain. Such procedures are e.g. single carrier method with PSK or QAM modulation.
  • the modulation method can be considered in equation (2) be borne by the data symbols d (i-m) the respective signal form of the modulation type used wear, if necessary with partial response pulse shaping.
  • channels with great memory, i. with long pulse duration can by the appropriate choice of the maximum delay M be equalized. This will naturally also the Observation duration N be correspondingly long.
  • the estimate of the scatterer coefficients in the Frequency range is preferably at Data transfer method used in the Frequency range work. Such methods are e.g. Multicarriermaschine like OFDM with the DVB-T procedure.
  • the data symbol D (n-k) is the waveform of the type of modulation used wear, shown here in the frequency domain.
  • the estimation is done via N samples in Time domain or N spectral components in Frequency range.
  • the estimation of the scatterer coefficients is preferably carried out by means of a recursive Kalman or an RLS algorithm, in which, after the initialization by the known symbol sequence, the channel is tracked even if the sequence is initially unknown.
  • a recursive Kalman or an RLS algorithm, in which, after the initialization by the known symbol sequence, the channel is tracked even if the sequence is initially unknown.
  • K (i) is the Kalman gain
  • P is the prediction state Covariance matrix
  • D is the data matrix resulting from (2) or (3)
  • W gives the noise covariance matrix
  • S Vector of the estimated scatter coefficients going through arranging the scatterers into a linear vector the matrix S is created.
  • r (i) is the received sampled Signal value (time or frequency range), i the index in Time or frequency direction.
  • Tree search methods are used. This is where starting from the channel estimated by the training sequence, for each of the potentially possible data sequences of Receiver built a path within a tree. For each of these paths will have a channel estimation with the Estimation of the scatterers performed and a metric according to (2) or (3) calculated. The data sequence with the Best metric is received as the most likely output. Due to the ML approach, the metric is one ML-metric.
  • This tree search method is schematically shown in FIG. 2 for represented binary symbols, ⁇ (x, ... y) denotes the metric for the assumed symbols x..y, S and the matrix of for the respective path determined scatterers.
  • the number of Indices indicates the depth of the tree, in the example up to a maximum of three.
  • the additionally marked path identifies the best path currently selected via the metric.
  • the described algorithm is a soft output algorithm, the next to the demodulated data also a measure of quality for the demodulation in the form of the metric can spend. Accordingly, it is possible not only the as to output the most likely ascertained data sequence, but even less likely. Hereby can downstream processing stages in the receiver, e.g. Decoders, get additional information based on Quality of reception.
  • the method can be further advantageous with a Convolution or block code as sole or inner Combine code of a concatenated code structure. It is known that convolution and block codes in the form of Display tree structures. A code affects the o.a. Tree structure so that not all paths, the if the code were ignored, too really exist. Therefore, such a tree is added Taking into account code information not all paths include.
  • FIG. Fig. 3 A tree derived from the example of FIG. 2 is shown in FIG Fig. 3 shown. By comparing the two trees will be clear that certain paths are not through the code existent.
  • the method according to the invention avoids this Disadvantages are not a priori.
  • the channel with Help the scatterer is modeled can by identifying the relevant scatterer the maximum occurring Delay and thus the dimension of the scatter matrix be determined. While in known methods this maximum length must always be taken into account inventive method adaptive to the maximum Delay of the channel received and the necessary Delay in demodulation and decoding be adjusted accordingly. Therefore, only in special channels, where significant Scatterer at high delays occur, the big extra Delay in demodulation and coding necessary become. Since the geometry of the scatterers is not Abrupt changes can occur when a scatterer occurs with great delay the dimension of the scatter matrix be increased adaptively. Conversely, it is also possible that the disappearance of such a scatterer the dimension the matrix is adaptively reduced.
  • L is the necessary delay. The minimum is determined via all possible data hypotheses d and all possible scatterers S.
  • the transmitted data can only be ISI in Cause time direction, i. in the past sent data affects later sent.
  • the described method can also without the Initialization work through training sequences.
  • processing is done with default values initialized, e.g. the matrix P becomes (4) as Unit matrix defaulted and the Scatterervektor S and Zero initialized.
  • the algorithm is then usually converge more slowly.
  • all possible Initial configurations for the data sequences are taken into account become.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Communication Control (AREA)
  • Error Detection And Correction (AREA)
  • Radio Transmission System (AREA)
  • Mobile Radio Communication Systems (AREA)

Claims (28)

  1. Procédé d'égalisation et de démodulation d'un signal de données transmis à un récepteur par l'intermédiaire d'un canal variable dans le temps selon un procédé de transmission de données de monoporteuse ou de multiporteuse,
       caractérisé en ce que
       dans le récepteur, on détermine à partir du signal de données reçu les coefficients de diffuseurs amortissement, temporisation et fréquence de Doppler des diffuseurs qui entraínent les distorsions de signal dans la voie, et le signal de données est égalisé et ensuite démodulé avec ces coefficients de diffuseurs ainsi calculés.
  2. Procédé selon la revendication 1,
       caractérisé en ce que
       le calcul des coefficients de diffuseurs et l'égalisation du signal de données s'effectuent dans la plage de temps.
  3. Procédé selon la revendication 2,
       caractérisé par
       son application avec les procédés de transmission de données de monoporteuse.
  4. Procédé selon la revendication 2,
       caractérisé par
       son application avec des procédés de transmission de données de multiporteuse en cas de réception de séquences de données connues.
  5. Procédé selon la revendication 1,
       caractérisé en ce que
       le calcul des coefficients de diffuseurs et l'égalisation du signal de données s'effectuent dans la plage de fréquence.
  6. Procédé selon la revendication 5,
       caractérisé par
       son application avec des procédés de transmission de données de multiporteuse.
  7. Procédé selon l'une quelconque des revendications précédentes,
       caractérisé en ce que
       les coefficients de diffuseurs sont déterminés au moyen d'un critère de la plus grande vraisemblance.
  8. Procédé selon la revendication 7,
       caractérisé en ce que
       les coefficients de diffuseurs sont déterminés en tant que minimum de la distance euclidienne entre le signal de réception et les données, démodulés dans le récepteur, du signal de réception et de tous les coefficients de diffuseurs possibles (formules 2 et 3).
  9. Procédé selon l'une quelconque des revendications précédentes,
       caractérisé en ce que
       un premier calcul des coefficients de diffuseurs est effectué à l'aide d'une séquence de données connue.
  10. Procédé selon la revendication 9,
       caractérisé en ce que
       le premier calcul des coefficients de diffuseurs est effectué par bloc au moyen d'une séquence de données globale.
  11. Procédé selon l'une quelconque des revendications précédentes 1 à 6 ainsi que 9 et 10,
       caractérisé en ce que
       un algorithme de Kalman est utilisé de façon itérative pour le calcul des coefficients de diffuseurs.
  12. Procédé selon l'une quelconque des revendications précédentes 1 à 6 ainsi que 9 et 10,
       caractérisé en ce que
       un algorithme de recursive-least-square est utilisé de façon itérative pour le calcul des coefficients de diffuseurs.
  13. Procédé selon la revendication 9 ou 10,
       caractérisé en ce que
       les coefficients de diffuseur calculés lors du premier calcul sont utilisés pour la réception consécutive de données utiles, les données étant égalisées et démodulées par bloc au moyen d'une séquence de données globale et les coefficients de diffuseurs calculés lors du premier calcul étant corrigés avec les données ainsi égalisées et démodulées par bloc.
  14. Procédé selon la revendication 9 ou 10,
       caractérisé en ce que
       les coefficients de diffuseurs calculés lors du premier calcul sont utilisés pour la réception ultérieure de données utiles, les coefficients de diffuseur calculés lors du premier calcul étant corrigés avec les données égalisées et démodulées selon un algorithme de Kalman ou de recursive-least-square.
  15. Procédé selon la revendication 13 ou 14,
       caractérisé en ce que
       pour la correction des coefficients de diffuseurs ainsi que pour la démodulation de données, on utilise un procédé de recherche d'arbre dans lequel, pour toutes les séquences de données possibles, on détermine respectivement les coefficients de diffuseurs et les métriques et on sélectionne ensuite à partir de la structure d'arbre les séquences de données qui présentent la meilleure métrique de la plus grande vraisemblance.
  16. Procédé selon la revendication 15,
       caractérisé en ce que
       les coefficients de diffuseurs correspondants aux meilleures séquences de données sélectionnées sont utilisés ultérieurement pour l'égalisation et la démodulation.
  17. Procédé selon la revendication 15 ou 16,
       caractérisé en ce que
       le choix des séquences de données s'effectue par bloc pour l'ensemble de la séquence de données considérée.
  18. Procédé selon la revendication 15 ou 16,
       caractérisé en ce que
       le choix des séquences de données est effectué après avoir atteint une profondeur de chemin prédéfinie de l'arbre.
  19. Procédé selon les revendications 15 à 18,
       caractérisé en ce que
       on utilise un algorithme de Metric-First avec le procédé de la recherche d'arbre.
  20. Procédé selon les revendications 15 à 18,
       caractérisé en ce que
       on utilise un algorithme de Breadth-First avec le procédé de recherche d'arbre.
  21. Procédé selon les revendications 15 à 18,
       caractérisé en ce que
       on utilise un algorithme de Depth-First avec le procédé de recherche d'arbre.
  22. Procédé selon les revendications 15 à 21,
       caractérisé en ce que
       avec le procédé de recherche d'arbre, la profondeur de chemin et le nombre de chemins sont modifiés de façon adaptative selon les coefficients de diffuseurs calculés.
  23. Procédé selon l'une quelconque des revendications 15 à 22,
       caractérisé en ce que
       la valeur de métrique est éditée également lors de l'édition de la séquence de données démodulée.
  24. Procédé selon les revendications 15 à 22,
       caractérisé en ce que
       en supplément de la séquence de données, on édite avec la meilleure métrique de la plus grande vraisemblance également d'autres prochaines séquences de données optimales avec une prochaine métrique optimale de la plus grande vraisemblance.
  25. Procédé selon l'une quelconque des revendications 15 à 24,
       caractérisé en ce que
       lors de la réception de signaux de données codés selon un code avec le procédé de la recherche d'arbre, on prend en compte seulement les séquences de données correspondant à des mots de code valables.
  26. Procédé selon la revendication 25,
       caractérisé en ce que
       avec le procédé de recherche d'arbre, on utilise en supplément un algorithme de Viterbi ou un algorithme APP en tenant compte du code.
  27. Procédé selon l'une quelconque des revendications précédentes,
       caractérisé en ce que
       le premier calcul des coefficients de diffuseurs n'est effectué qu'avec des séquences inconnues de données utiles et en ce que, lors de l'initialisation des algorithmes, on utilise des valeurs par défaut au lieu de séquences d'entraínement et de synchronisation.
  28. Procédé selon l'une quelconque des revendications 7 à 10,
       caractérisé en ce que
       le nombre maximal des coefficients de diffuseurs à prendre en compte est adapté dans les algorithmes à l'aide des coefficients de diffuseurs calculés respectivement auparavant.
EP03760586A 2002-06-24 2003-05-14 Procede d'egalisation et de demodulation d'un signal de donnees transmis par l'intermediaire d'un canal variable dans le temps Expired - Lifetime EP1516470B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10228159A DE10228159A1 (de) 2002-06-24 2002-06-24 Verfahren zur Entzerrung und Demodulation eines über einen zeitveränderlichen Kanal übertragenen Datensignals
DE10228159 2002-06-24
PCT/EP2003/005068 WO2004002099A1 (fr) 2002-06-24 2003-05-14 Procede d'egalisation et de demodulation d'un signal de donnees transmis par l'intermediaire d'un canal variable dans le temps

Publications (2)

Publication Number Publication Date
EP1516470A1 EP1516470A1 (fr) 2005-03-23
EP1516470B1 true EP1516470B1 (fr) 2005-10-05

Family

ID=29761352

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03760586A Expired - Lifetime EP1516470B1 (fr) 2002-06-24 2003-05-14 Procede d'egalisation et de demodulation d'un signal de donnees transmis par l'intermediaire d'un canal variable dans le temps

Country Status (17)

Country Link
US (1) US20050220231A1 (fr)
EP (1) EP1516470B1 (fr)
KR (1) KR20050007432A (fr)
CN (1) CN1663212A (fr)
AT (1) ATE306166T1 (fr)
AU (1) AU2003232774B2 (fr)
BR (1) BR0307433A (fr)
CA (1) CA2474559A1 (fr)
DE (2) DE10228159A1 (fr)
DK (1) DK1516470T3 (fr)
ES (1) ES2249733T3 (fr)
HU (1) HU225835B1 (fr)
IL (1) IL165903A0 (fr)
MX (1) MXPA04010997A (fr)
NO (1) NO20050321L (fr)
WO (1) WO2004002099A1 (fr)
ZA (1) ZA200404576B (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7596191B2 (en) * 2005-12-08 2009-09-29 Nokia Corporation Apparatus, method and computer program product providing a computationally efficient maximum likelihood joint synchronization and channel estimation algorithm
DE102006029464A1 (de) * 2005-12-23 2007-06-28 Rohde & Schwarz Gmbh & Co. Kg Verfahren und Entzerrer zur Detektion von über einen zeitveränderlichen Übertragungskanal übertragenen Datensymbol-Sequenzen aus einem diese enthaltenden Empfangssignal
DE102006014064A1 (de) * 2005-12-23 2007-06-28 Rohde & Schwarz Gmbh & Co. Kg Verfahren und Entzerrer zur Entzerrung einer über einen zeitveränderlichen Übertragungskanal empfangenen Datensymbol-Sequenz
CN105548711B (zh) * 2015-12-08 2018-06-12 北京航空航天大学 一种多频信息滤波递推解调方法
CN109274423B (zh) * 2018-10-22 2020-03-17 南京邮电大学 一种移动性可见光通信信道均衡方法

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3997841A (en) * 1974-10-08 1976-12-14 International Standard Electric Corporation Time domain equalizer for broadband communication systems
US4959656A (en) * 1989-10-31 1990-09-25 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Efficient detection and signal parameter estimation with application to high dynamic GPS receiver
US5859874A (en) * 1994-05-09 1999-01-12 Globalstar L.P. Multipath communication system optimizer
US5729558A (en) * 1995-03-08 1998-03-17 Lucent Technologies Inc. Method of compensating for Doppler error in a wireless communications system, such as for GSM and IS54
US6134277A (en) * 1997-09-04 2000-10-17 Ericsson Inc System and method for self-adaptive maximum likelihood sequence detection
US6411649B1 (en) * 1998-10-20 2002-06-25 Ericsson Inc. Adaptive channel tracking using pilot sequences
WO2000031937A1 (fr) * 1998-11-24 2000-06-02 Infineon Technologies Ag Procede pour la compensation de dysfonctionnements lors de la production d'un signal par modulation multitonalite discrete, et circuit pour la mise en oeuvre de ce procede
US6320919B1 (en) * 1998-11-30 2001-11-20 Ericsson Inc. Adaptive channel characterization using decoded symbols
FR2787199B1 (fr) * 1998-12-11 2001-03-09 Thomson Csf Procede de detection, notamment de petites cibles marines
US6757339B1 (en) * 2000-07-24 2004-06-29 Nortel Networks Limited Minimum mean-squared error block-decision feedback sequence estimation in digital communication systems
US6983125B2 (en) * 2001-09-25 2006-01-03 Qualcomm Incorporated Method and apparatus for varying the length of an adaptive equalizer based on doppler frequency

Also Published As

Publication number Publication date
IL165903A0 (en) 2006-01-15
CN1663212A (zh) 2005-08-31
HUP0500020A2 (hu) 2005-05-30
ES2249733T3 (es) 2006-04-01
NO20050321L (no) 2005-01-20
US20050220231A1 (en) 2005-10-06
CA2474559A1 (fr) 2003-12-31
MXPA04010997A (es) 2005-05-27
AU2003232774A1 (en) 2004-01-06
HU225835B1 (en) 2007-10-29
ZA200404576B (en) 2005-06-09
AU2003232774B2 (en) 2007-05-10
DE10228159A1 (de) 2004-01-22
DK1516470T3 (da) 2006-02-20
DE50301325D1 (de) 2005-11-10
ATE306166T1 (de) 2005-10-15
WO2004002099A1 (fr) 2003-12-31
KR20050007432A (ko) 2005-01-18
BR0307433A (pt) 2004-12-28
EP1516470A1 (fr) 2005-03-23

Similar Documents

Publication Publication Date Title
DE102014008347B4 (de) Verfahren und vorrichtung zur kanalschätzung und ofdm-empfänger
DE69527436T2 (de) Verfahren und einrichtung zur kanalschätzung
DE19614543C1 (de) Entzerrer mit erweiterter Kanalschätzung für einen Empfänger in einem digitalen Übertragungssystem
DE60214061T2 (de) Turbo-Empfänger und das entsprechende Verfahren für ein MIMO System
DE69515684T2 (de) Digitale datendekodierungsanordnung unter verwendung einer variablen entscheidungstiefe
DE19614544C1 (de) Entzerrer mit einem Sequenzschätzverfahren mit Zustandsreduktion für einen Empfänger in einem digitalen Übertragungssystem
DE102015107080B3 (de) Verfahren und Vorrichtungen zur Kanalschätzung für Mobilsysteme ungenügender zyklischer Präfixlänge
EP0490427B1 (fr) Récepteur ayant au moins deux branches de réception
DE60028012T2 (de) Kalman-entzerrung in mehrträgerempfängern
DE69621228T2 (de) Verfahren, modul und vorrichtung zum empfang digitaler signale mit iterativer arbeitsweise
DE69932118T2 (de) Kanalschätzung unter Verwendung von Weichentscheidungsrückkoppelung
DE102009030959B4 (de) Kanalschätzer und Verfahren zur Kanalschätzung
EP2140639B1 (fr) Procédé et dispositif de détermination d'une réponse impulsionnelle de canal non raccourcie dans un système de transmission ofdm
DE60011224T2 (de) Ofdm-empfänger mit adaptivem entzerrer
EP1516470B1 (fr) Procede d'egalisation et de demodulation d'un signal de donnees transmis par l'intermediaire d'un canal variable dans le temps
EP0963084A2 (fr) Récepteur pour système de transmission numérique
EP0545159B1 (fr) Procédé de transmission radio numérique avec estimation de la résponse impulsionnelle du canal
AT511343B1 (de) Verfahren zum entzerren eines mehrträgersignals hinsichtlich interträgerinterferenz
DE60311150T2 (de) Gerät und vorrichtung zur verarbeitung einer kanalimpulsantwort
DE60032906T2 (de) Verfahren und Vorrichtung zur Kanalschätzung, insbesondere für ein Mobiltelefon
DE19523327C2 (de) Verfahren zur verbesserten Schätzung der Impulsantwort eines Übertragungskanals
EP1316182B1 (fr) Egalisation de canal amelioree pour recepteur de telephonie mobile
EP1964344B1 (fr) Procédé et égaliseur destinés à la détection de séquences de symboles de données transmises sur un canal de transmission variable dans le temps, à partir d'un signal de réception contenant ces séquences
DE60318398T2 (de) Verfahren zur Störungsunterdrückung mittels einer iterativen, semi-blinden Kanalschätzung
EP0654925B1 (fr) Procédé et système pour poursuivre la réponse impulsionelle d'un canal sélectif en fréquence

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20040602

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL LT LV MK

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REF Corresponds to:

Ref document number: 50301325

Country of ref document: DE

Date of ref document: 20051110

Kind code of ref document: P

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20051029

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060105

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060105

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2249733

Country of ref document: ES

Kind code of ref document: T3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060406

REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060531

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20060706

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070531

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060514

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CZ

Payment date: 20080505

Year of fee payment: 6

Ref country code: DK

Payment date: 20080522

Year of fee payment: 6

Ref country code: ES

Payment date: 20080523

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20080521

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: PT

Payment date: 20080505

Year of fee payment: 6

Ref country code: TR

Payment date: 20080430

Year of fee payment: 6

Ref country code: BE

Payment date: 20080527

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20080523

Year of fee payment: 6

Ref country code: SE

Payment date: 20080523

Year of fee payment: 6

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20051005

REG Reference to a national code

Ref country code: PT

Ref legal event code: MM4A

Free format text: LAPSE DUE TO NON-PAYMENT OF FEES

Effective date: 20091116

BERE Be: lapsed

Owner name: *ROHDE & SCHWARZ G.M.B.H. & CO. K.G.

Effective date: 20090531

REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090514

Ref country code: CZ

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090514

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20091201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091116

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090531

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20090516

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090516

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090515

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090514

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 14

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FI

Payment date: 20170519

Year of fee payment: 15

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 16

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180514

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20220531

Year of fee payment: 20

Ref country code: GB

Payment date: 20220523

Year of fee payment: 20

Ref country code: FR

Payment date: 20220523

Year of fee payment: 20

Ref country code: DE

Payment date: 20220519

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 50301325

Country of ref document: DE

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20230513

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230525

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20230513